Question

The equation of a circle C, with centre O, is:

x2 + y2 = 225
(a) Find the coordinates of the centre O.
(b) Find the radius of C.

Answer 1

a) The center coordinates O is (0,0)

b) The radius C = 15

Explanation:

The given equation of the circle is :
`x^(2)  +  y^(2)  = 225`

Now, general form of the equation of the circle is:

`(x-h)^(2)  + (y - k)^(2)   = r^(2)`

where (h,k) are the center co -ordinates and r is the radius of the circle.

Comparing the general equation with the given equation, we get

`(x-0)^(2)  + (y - 0)^(2)   = (15)^(2)`

So, here the center coordinates (h,k) = (0,0)

And the radius of the given circle is r = 15